The complaint, filed in the Superior Court on March 22, 1978, alleges that the plaintiff sustained injuries in a fall on September 20, 1977, resulting from the negligence of one of the defendant’s employees for whose conduct the defendant is responsible. On February 2, 1981, the defendant filed a motion for dismissal or summary judgment, which the trial judge treated as a motion for summary judgment. The basis of the motion was that G. L. c. 258 provides the plaintiff’s only remedy, and § 4 of that chapter requires a plaintiff to present a claim in writing to the executive officer of the appropriate public employer *782before commencing suit, which the plaintiff had not done. The judge denied the motion, filed a memorandum of decision, and, at the plaintiffs request, reported the case to the Appeals Court. We took the case on our own motion. We affirm.
Statute 1978, c. 512, § 15, amended the General Laws by striking out former c. 258 and inserting a new c. 258. Statute 1978, c. 512, § 15, was approved on July 20, 1978, and by § 16 was made effective upon passage and applicable to all causes of action arising on or after August 16,1977. The plaintiff’s cause of action arose on September 20, 1977, the day he was injured, and c. 258 applies to it. However, c. 258 became effective July 20, 1978, and is to be read as of that day, and not as of August 16, 1977, as the defendant’s argument implies.
General Laws c. 258, § 4, provides in relevant part that “[a] civil action shall not be instituted against a public employer on a claim for damages under this chapter unless the claimant shall have first presented his claim in writing to the executive officer of such public employer.” By its terms, St. 1978, c. 512, § 16, reflects the distinction between the cause for which a civil action may be brought (cause of action) and the action itself. General Laws c. 258 applies retroactively to causes of action arising on or after August 16, 1977, but it does not apply retroactively to actions brought before its effective date, July 20, 1978. Thus, after July 20, 1978, no civil action may be instituted against a public employer on a claim under c. 258 arising out of injuries occurring on or after August 16, 1977, without a prior presentment of written claim to the public employer’s executive officer. As to actions instituted before the statute’s effective date, presentment is not required. Therefore, the plaintiff was not required to present a written claim before instituting this action on March 22, 1978.
In Pruner v. Clerk of the Superior Court, 382 Mass. 309 (1981), we affirmed a judgment dismissing a complaint. One of the grounds for dismissal was that the action was commenced without compliance with c. 258, § 4. Id. at *783316. Pruner is clearly distinguishable from the present case because the action there was commenced after the effective date of c. 258. Id. at 309-310.
The judge’s denial of the defendant’s motion for summary judgment is affirmed.
So ordered.