National Medical Support Notice

[Morgan]

Hello, 

My client just recieved a NMSN for an employee on May 30th and the date on the NMSN in the top right corner is May 22nd (the date for which the letter was produced and sent I believe). The recieving department sent the notice to Human Reources (Also the Plan Administrator) in early June at which time the HR team deemed it was a legitimate notice. The earliest enrollment date would then be the first of the following month from my understanding, making the effective date 7/1?

The Medical Carrier agreed that this effective date was properly determined, however the Dental & Vision carrier is saying that we have to make the benefits effective on 5/22 since that is the date on the NMSN. The Employer didn't even have the notice on 5/22 so this seems incorrect. Has anyone heard of a carrier doing this? Maybe it's an inexperienced employee at the carrier that we are dealing with or maybe I'm interpretting the NMSN instructions incorrectly.

Any insight is greatly appreciated.