concurring in the judgment only.
I concur in the majority’s judgment reversing the holding of the court of appeals. Because I do not agree, however, that the defendant’s claim is properly characterized as a motion to correct an illegal sentence, and therefore that it may be brought pursuant to Crim. P. 35(a), I would find it unnecessary to reach the merits of the claim. Furthermore, even if I considered it necessary to reach the merits, as the majority does, I believe the matter is easily resolved by reference to the applicable statutes themselves, without broadly defining the term “factual basis” for all purposes.
Although I wholeheartedly agree that the defendant pled guilty neither to “an offense involving unlawful sexual behavior” nor to an offense “for which the factual basis involved an offense involving unlawful sexual behavior,” section 17 — 2—201(5)(a), C.R.S. (2005), I write separately to explain why I believe the majority’s treatment of Crim. P. 35(a) and its exegesis of the term “factual basis” should be viewed with caution outside the narrow (and highly unusual) context of a criminal defendant seeking to be classified as a sex offender, which is actually before the court today.
Unlike the majority, I consider it clear that the defendant’s claim challenges the validity of his conviction for burglary (with the intent to harass), rather than the legality of his sentence for that conviction. See maj. op. at 416. The trial court found a factual basis for that offense, entered judgment for that offense, and imposed a sentence mandated by the legislature for that offense. The defendant does not assert the illegality of the sentence imposed for the offense for which his plea was accepted; he asserts that the record supports the entry of a plea to (what in effect is) a different offense altogether.
Because the trial court never found a factual basis for unlawful sexual behavior and never accepted a plea based on such behavior, the defendant’s challenge to the factual basis for his offense only secondarily implicates the legality of his sentence. Even according to the defendant’s theory, his sentence is illegal only to the extent that the court erred in failing to find and enter judgment on (what the defendant considers to be) mitigation for his crime of burglary. Such a claim does not challenge the legality of a sentence within the contemplation of Crim. P. 35(a). Were Crim. P. 35(a) to extend so far, virtually any challenge to a defendant’s conviction could be couched in terms of its secondary effect on his sentence, obliterating any distinction between Crim. P. 35(a) and Crim. P. 35(c), and the separate purposes and limitations of each.
Permitting such claims to be brought as challenges to the authority, or jurisdiction, of the sentencing court, without time limitation of any kind, is particularly problematic in the context of sex offender sentencing. In Martin v. People, 27 P.3d 846 (Colo.2001), we held in effect that when the general assembly changed the sentencing scheme in 1993 to mandate that felony sentences include a period of parole supervision extending up to five years beyond the term of incarceration imposed by the court, it intended to exempt sex offenders, despite expressly naming them and singling them out for the longest possible period of “mandatory parole.” Since that *423time, classifying an offense as one of the sex offenses described by section 17-2-201(5) has had particular significance for parole consequences. It is often, however, unclear whether the parole consequences of section 17-2-201(5) will be advantageous or disadvantageous for a particular defendant until after (and sometimes well after) he has been sentenced.
Although the majority refers to the two-track parole system as including “mandatory” and “discretionary” parole, maj. op. at 415-416, no system of parole mandating release when an inmate becomes eligible for parole has existed in this jurisdiction for decades. Under the current regime, once a defendant becomes statutorily eligible for parole, it is within the discretion of the parole board to grant or deny release, and generally to set the conditions of his parole, regardless of the track in which a defendant’s conviction places him. Although the length of parole for felony offenses other than those governed by section 17-2-205(5) is ostensibly mandated by statute, even that time period can be shortened in the discretion of the board. See § 18-1.3~401(l)(a)(V)(B), C.R.S. (2005). The real difference between the two tracks or systems of parole resides in the fact that the “mandatory” period of parole, required by section 18-1.3-401, may be imposed, whether or not that amount of time remains unserved on the defendant’s court-imposed sentence to incarceration.
Therefore whether a defendant’s offense is treated by section 17-2-201(5) as a sex offense or not, he becomes eligible for parole according to the same considerations, and the parole board has the same discretion to grant or deny parole. Because a sex offender could be kept under parole supervision for as long as five years, pursuant to section 17-2-201(5), while the statutorily prescribed period of parole for non-sex offenses could be as low as one year, a sex offender may actually be subjected to a longer period of parole than if he were convicted for an offense not involving unlawful sexual behavior. However, because a sex offender cannot be held on parole for any longer than the period remaining on his sentence to incarceration, the advanta-geousness of one parole track as opposed to the other, for any particular defendant, will likely turn on the length of the defendant’s original sentence, as well as his assessment of the likelihood that he will be released on parole sooner (rather than later) during the service of his sentence, and the likelihood that the parole board will decide to keep him under supervision for a shorter (rather than a longer) period of time.
Because any defendant pleading to a crime involving (or having a factual basis involving) unlawful sexual behavior will almost certainly be required to register as a sex offender upon release from custody, he will remain subject to a form of supervision, even after being released from parole. His considerations in seeking (or avoiding) classification as a sex offender will therefore be complex and likely to change, long after his plea has been entered. Once it becomes clear to a defendant that he is unlikely to be granted parole, whether or not he has already been rejected; or once the unserved remainder of his sentence to incarceration becomes small, relative to the mandatory parole for his level of felony, the advantages of being classified as a sex offender are likely to rise in his calculations. It is clear to me that Crim. P. 35(a) was not intended to permit defendants to seek classification as a sex offender based on the particular facts of their crimes, once it becomes advantageous for their particular situation.
The defendant in this case first moved for correction of an illegal sentence after serving more than two years of a six year sentence and some six years after entering his bargained-for plea. By statute, he could easily have become eligible for parole by that time. See §§ 17-22.5-403 and 405, C.R.S. (2005). For the reasons I have already articulated, I believe his claim raises a challenge to the validity of his conviction rather than the legality of his sentence. Even if he were able to couch his claim in terms otherwise permitting a motion for post-conviction relief pursuant to Crim. P. 35(e), I would find his challenge to his six-year-old plea time-barred. See People v. McPherson, 53 P.3d 679, 681-82 (Colo.App.2001); People v. Cummins, 37 P.3d 507, 509 (Colo.App.2001).
*424If, like the majority, I considered it necessary to reach the merits of the defendant’s claim, I would find it clear from the context that the legislature used the term “factual basis” in reference to the factual basis required in this jurisdiction prior to the acceptance of a guilty plea. In 1996, the legislature expanded the class of sexually-related offenses governed by section 17-2-201(5)(a), changing the description from “a sex offense, as defined in section 16-13-202(5), C.R.S. [The Colorado Sex Offenders Act of 1968]” to “an offense involving unlawful sexual behavior or for which the factual basis involved an offense involving unlawful sexual behavior, as defined in section 18-3-412.5(1), C.R.S. [Sex offenders' — duty to register — penalties].” This disjunctive construction, lifted in its entirety from the registration statute, included any offense “for which the factual basis involved an offense involving unlawful sexual behavior,” in addition to any offense “involving” unlawful sexual behavior. Consequently, it is plainly unnecessary for the majority to expansively define “factual basis” to include elements or sentencing factors found by a trier of fact because they are already included as offenses “involving” unlawful sexual behavior. See maj. op. at 418. Rather, it seems manifest that the disjoined clause, referencing offenses “for which the factual basis involved an offense involving unlawful sexual behavior,” was clearly added specifically to encompass guilty pleas for which no such finding existed, but for which a factual basis sufficient to accept the plea did.
Were this language and history insufficient in itself, the general assembly has now, with the 2002 reorganization of the registration statutes (cross-referenced in the 2002 amendment to section 17-2-201(5)(a), C.R.S. (2005)), specified the persons who will be “deemed to be convicted of an offense, the underlying factual basis of which involves unlawful sexual behavior.... ” See § 16 — 22—103(2)(c), C.R.S. (2005). While the more recent provisions alter somewhat the formula for offenses requiring registration, and by their own terms limit their applicability to convictions entered after July 2002, I believe they clarify the legislature’s intent with respect to the inclusion of offenses not themselves enumerated as unlawful sexual behavior. Since 2002, the statute expressly prohibits a person from being deemed to have been convicted of an offense the underlying factual basis of which involves unlawful sexual behavior, unless the judgment of conviction specifies that the person is convicted of such an offense and specifies the particular crime of unlawful sexual behavior involved. See § 16-22-103(2)(c)(IV).
Were I to reach the merits, I would therefore find, from the statutes themselves and without reference to case law developed in other contexts and for other purposes, that a defendant has pled guilty to a sex offense, for both parole and registration purposes, only if the offense to which he pled was itself an offense of unlawful sexual behavior or if the court found, and the defendant accepted, that the offense to which he pled included a factual basis involving unlawful sexual behavior. Because, however, I consider it clear that the defendant’s claim alleges a failure to sentence him for the offense he alleges that he actually committed, rather than a failure to legally sentence him for the offense to which he pled guilty, I would hold that his claim was not properly raised as a motion to correct an illegal sentence, pursuant to Crim. P. 35(a).
I therefore concur only in the judgment of the majority. I am authorized to state that JUSTICE KOURLIS joins in this concurrence.