Petitioner Byrdie Turman-Kent seeks review of an order of the Merit Systems Protection Board dismissing her petition *1267for review of the decision of an administrative judge on grounds of untimeliness. We affirm.
I
Ms. Turman-Kent married Jesse W. Kent in 2001. Mr. Kent had previously retired unmarried under the Civil Service Retirement System (“CSRS”) and had elected to receive an annuity payable during his lifetime with no survivor benefits. Mr. Kent died in 2003, and Ms. TurmanKent later applied to the Office of Personnel Management (“OPM”) for survivor annuity benefits as Mr. Kent’s widow. That request was denied because Mr. Kent had never elected to provide a survivor annuity for Ms. Turman-Kent.
Ms. Turman-Kent asked OPM to reconsider its decision based on a telephone conversation that she and her late husband allegedly had with an OPM employee regarding Mr. Kent’s election of survivor annuity benefits. After considering that new evidence, OPM affirmed its determination that Ms. Turman-Kent was ineligible for survivor annuity benefits. In a January 2004 letter, OPM explained that a previously unmarried retiree such as Mr. Kent could have elected to receive a reduced lifetime annuity with survivor benefits for a new wife only by notifying OPM of his intentions in a signed writing within two years of his marriage. See 5 U.S.C. § 8339(k)(2)(A). That letter also notified Ms. Turman-Kent of her right to appeal OPM’s decision to the Board.
Ms. Turman-Kent filed an appeal with the Board contesting OPM’s reconsideration decision. In May 2004, the administrative judge who was assigned to her case upheld OPM’s decision. The administrative judge explained that Ms. TurmanKent had provided the Board with no basis for waiving the two-year statutory time limit for election of survivor benefits. The administrative judge’s initial decision was sent to Ms. Turman-Kent with the following notice:
This initial decision will become final on June 21, 2004, unless a petition for review is filed by that date or the Board reopens the case on its own motion. This is an important date because it is usually the last day on which you can file a petition for review with the Board.... These instructions are important because if you wish to file a petition, you must file it within the proper time period.
Ms. Turman-Kent did not file a petition for review by the Board before June 21, 2004, and the administrative judge’s initial decision therefore became the final decision of the Board.
Ms. Turman-Kent ultimately filed a petition for review with the Board on August 11, 2010, more than six years after the initial decision became final. Upon receiving her petition, the clerk of the Board informed her that it was untimely filed and provided her with an opportunity to file a motion to accept the filing as timely or waive the time limit for good cause. In her motion, Ms. Turman-Kent alleged that she had long suffered from short-term and long-term memory loss due to an intracerebral hemorrhage suffered in 1986. She also represented that her illness had “flare[d] out of control” after May 2004 due to extreme stress, but that her medical condition had “shifted” and “improved” at some time after mid-2006, when she moved to Illinois. Ms. Turman-Kent stated in her motion that her disability “made it difficult to find [her] records in order to accurately chronicle events necessary to respond in a timely manner.” She attached a one-page letter from an Illinois physician, Dr. Jean Cavanaugh, who stated that she had examined Ms. Turman-Kent before she moved to Georgia in 2002 and again after July 2006 for cognitive defects *1268attributable to her intracerebral hemorrhage. Dr. Cavanaugh described Ms. Turman-Kent’s condition as “stable but a major impairment” since the late 1980s. Dr. Cavanaugh stated that “[tjhere is no doubt in my mind that she was unable to process paper work after her husband’s death.”
After considering Ms. Turman-Kent’s motion, the Board denied her petition for review as untimely filed. The Board found the statement of Dr. Cavanaugh insufficient to support Ms. Turman-Kent’s claim because Dr. Cavanaugh had not examined Ms. Turman-Kent for several years during the six-year period of delay in filing her petition for review. The Board noted that Dr. Cavanaugh did not allege that she reviewed Ms. Turman-Kent’s medical records for that time period, and it observed that Dr. Cavanaugh’s statement post-dated the filing of Ms. Turman-Kent’s petition for review. Finding no credible medical evidence regarding Ms. Turman-Kent’s condition between June 2004 and July 2006, the Board determined that Ms. Turman-Kent “ha[dj not submitted sufficient evidence to support that her medical condition impaired her ability to timely file her petition for review, or to request an extension of time.”
II
Ms. Turman-Kent bears a “heavy burden” to overturn the Board’s determination that good cause has not been shown for her untimely filing. Zamot v. Merit Sys. Prot. Bd., 332 F.3d 1374, 1377 (Fed. Cir.2003); see Mendoza v. Merit Sys. Prot. Bd., 966 F.2d 650, 653 (Fed.Cir.1992) (en banc) (“whether the regulatory time limit for an appeal should be waived based upon a showing of good cause is a matter committed to the Board’s discretion”). Board regulations require tardy petitioners to file a “specific and detailed description of the circumstances causing the late filing, accompanied by supporting documentation or other evidence.” 5 C.F.R. § 1201.114(f). The Board has held that when petitioners allege delay for medical reasons, they must affirmatively identify medical evidence that addresses the entire period of delay. Jerusalem v. Dep’t of the Air Force, 107 M.S.P.R. 660, 663, affd, 280 Fed.Appx. 973 (Fed.Cir.2008).
Ms. Turman-Kent did not provide the Board with medical evidence that accounted for the entire six-year period of delay at issue in this case. In particular, there was no medical evidence regarding her condition between June 2004 and July 2006. The Board found it probative that Dr. Cavanaugh had not examined Ms. Turman-Kent during the year prior to her husband’s death or for a three-year period after his death. Ms. Turman-Kent states that she saw two other physicians during that period when she lived in Georgia, yet no evidence from either of those physicians was presented, nor did Dr. Cavanaugh purport to rely on any such evidence in her evaluation of Ms. Turman-Kent’s condition during that period. The dissent refers to a letter written by Ms. Turman-Kent’s neurologist in 1988. That letter, which predates the period in question by 16 years, simply addresses the circumstances giving rise to Ms. Turman-Kent’s illness and the fact that she would not be able to continue in her previous profession as an accountant.
We have recognized that the length of delay is an important factor for the Board to consider in determining whether a petitioner has shown good cause for an untimely filing. Walls v. Merit Sys. Prot. Bd., 29 F.3d 1578, 1582 (Fed.Cir.1994). The length of delay in this case — six years' — is exceptional. Even in cases of ongoing illness, the Board has found the absence of medical evidence covering the entirety of a multi-year period to be fatal to a finding of good cause. See, e.g., Wilson v. Office of Pers. Mgmt., 83 M.S.P.R. *1269223, 227 (1999) (noting that documentation of mental illness from 1988 to 1996 did not excuse absence of medical evidence from period between 1996 and 1999); Phillips v. Dep’t of the Army, 77 M.S.P.R. 305, 309 (1998) (evidence of “recurrent major depressive disorder” diagnosed in 1995 did not establish petitioner’s condition between 1995 and 1997). The Board did not abuse its discretion in demanding a well-documented explanation of the cause for Ms. Turman-Kent’s delay in filing her appeal.
Before this court, Ms. Turman-Kent has submitted several pieces of medical evidence that were not presented to the Board. That evidence includes several annual disability certifications issued to hér by the Social Security Administration, numerous pharmacy reports of medicines prescribed to her between 2003 and 2011, and an additional letter from Dr. Cavanaugh dated March 2011 that elaborates on Ms. Turman-Kent’s condition. Because those items were not presented to the Board, they are not part of the record on appeal and are not properly before us. See Mueller v. U.S. Postal Serv., 76 F.3d 1198, 1201-02 (Fed.Cir.1996) (“Because we are limited to reviewing decisions of the Board based on the record before the deciding official, we decline to base our judgment on evidence that was not part of the record before the administrative judge.”).
The dissent relies on our decision in Pyles v. Merit Systems Protection Board, 45 F.3d 411 (Fed.Cir.1995). The petitioner in Pyles presented the Board with a medical finding that she had “increasingly severe dementia,” a “progressive organic brain disease[]” defined by “the loss of intellectual faculties.” This court concluded that unrebutted medical evidence of dementia was sufficient to establish good cause for untimely filing. Id. at 415. The dissent argues that because brain cell death caused by an intracerebral hemorrhage is permanent, Pyles requires the Board to adopt a presumption that Ms. Turman-Kent’s cognitive function could not have improved at any point during her six-year delay in filing a petition for review. However, our holding in Pyles was predicated not only on the permanence of dementia but also on its very nature as “[a] structurally caused permanent or progressive decline in several dimensions of intellectual function that interferes substantially with the individual’s normal social or economic activity.” Id. The medical literature cited by the dissent does not suggest that cognitive function never improves in persons who have suffered an intracerebral hemorrhage.
Ms. Turman-Kent’s motion before the Board states that her illness had temporarily “flare[d] out of control,” but that at some later time her condition had “shifted” and “improved” and she “became better able to remember business details, at times.” That statement conflicts with Dr. Cavanaugh’s assessment of Ms. TurmanKent’s condition as “stable” throughout the six-year period of delay. Moreover, Ms. Turman-Kent timely filed pleadings before OPM in 2003 and before the Board in 2004. Those filings were made during the multiyear period in which she was not under the care of Dr. Cavanaugh, and they undermine her claim of an ongoing, irreversible medical condition suffered a quarter-century ago that has permanently prevented her from timely filing paperwork in support of her claim. See Ortiz v. Dep’t of Justice, 103 M.S.P.R. 621, 630 (2006) (finding no good cause for delay due to ongoing illness where evidence did not explain change in circumstances between period in which appellant complied with Board deadlines and period in which he failed to comply); Choco v. Office of Pers. Mgmt., 69 M.S.P.R. 638, 641 (1996) (rejecting appellant’s contention that he was precluded from timely filing a petition for review for more than five years, “especially in view of the fact *1270that he was able to file a petition for review with the Board’s regional office” four months before his petition for review was due for filing); Hawkins v. Dep’t of the Navy, 67 M.S.P.R. 559, 562 (1995) (no good cause for eight-month delay in filing petition for review when appellant “was capable of filing a petition for enforcement [of a settlement agreement]” early in that period); Sing v. Dep’t of the Navy, 51 M.S.P.R. 251, 254 (1991) (finding appellant’s allegations of incapacity to file paperwork in a timely fashion undermined by timely filing of other papers during the period in question).1
Ms. Turman-Kent also alleges that she did not receive “proper forms” in a timely manner and was therefore unable to file a timely petition for review. The document that she references is the January 2004 OPM reconsideration decision letter that denied her claim for survivor benefits. Following her receipt of that letter, Ms. Turman-Kent filed a timely appeal with the Board contesting OPM’s denial of her claim for benefits. The OPM reconsideration letter is irrelevant to the timeliness of her subsequent petition for review by the full Board of the administrative judge’s initial decision, which is the issue before us. Ms. Turman-Kent has never alleged that she did not receive the administrative judge’s initial decision informing her of the deadline for submitting a petition for review to the full Board.
Finally, Ms. Turman-Kent states that she was hospitalized for hallucinations and seizures during the period following her return to Illinois. That allegation does not constitute evidence of her condition between June 2004 and July 2006 because she did not return to Illinois until after that time period. Her statement therefore cannot undermine the Board’s ruling. Accordingly, we affirm the dismissal of Ms. Turman-Kent’s petition for review as untimely.
No costs.
AFFIRMED
. The procedures set forth in this court's decision in French v. Office of Personnel Management, 810 F.2d 1118 (Fed.Cir.1987), for claimants seeking disability retirement benefits are available only upon a showing of incompetence. See Rapp v. Office of Pers. Mgmt., 483 F.3d 1339, 1341 (Fed.Cir.2007); Frank v. Office of Pers. Mgmt., Ill M.S.P.R. 206, 209 (2009) (same for claimant seeking survivor annuity). In this case, the Board found that Ms. Turman-Kent has not shown that she was incompetent or otherwise incapable of filing a petition for review during the entire period of delay. Therefore, the decision in French does not provide an independent ground for reversing the Board's ruling in this case.