(1) A party may amend his claim or complaint as to the time, place, cause, or nature of the injury, as a matter of right, at any time prior to a conference on a form provided by the Department. At the time of a conference or thereafter, a party may amend such claim or complaint only by filing a motion to amend with an administrative judge. Such a motion shall be allowed by the administrative judge unless the amendment would unduly prejudice the opposing party.

(2) A party may amend a claim or complaint on a form provided by the Department as to a party as a matter of right at any time prior to a conference whenever the controversy created by the amended claim or complaint arose out of conduct, incident, or series of occurrences set forth or attempted to be set forth in the original claim or complaint.

(3) No amendment to a claim or complaint may be made except as provided by MGL c. 152 and 452 CMR 1.00. Any party shall be allowed a reasonable period of time to prepare a defense to an amended claim or complaint. Such period shall not exceed 45 calendar days from the date of notice of the amendment, unless an administrative judge finds that additional time to prepare a defense is needed.