It's official, Tewksbury is changing Congressional Districts.

Massachusetts Governor Deval Patrick signed House Bill 3798, “An Act Establishing Congressional Districts” Monday, making the Special Joint Committee on Redistricting's proposal for new state Congressional Districts official.

The plan moves Tewksbury from Congresswoman Niki Tsongas' 5th Congressional District into Congressman John Tierney's 6th District. The changes will take effect in January, 2013, meaning the first chance Tewksbury voters will get the chance to vote for or against Tierney will be the fall of 2012.

Tierney, a Democrat from Salem, has said he will definitely run for re-election. Already throwing their hats in the ring to challenge Tierney are Republicans Bill Hudak (whom Tierney beat in 2010) and Richard Tisei.

Here's a look at come o the other changes as a result of House Bill 3798 being signed.

• Congresswoman Niki Tsongas’s district would gain the communities Gardner, Pepperell, Clinton, Fitchburg, Lunenburg, and Marlborough while losing Billerica, Tewksbury, and part of Andover.
• The minority population of the Eighth Congressional district, held by Congressman Michael Capuano, will grow from 52 percent to 56.6 percent.
• The districts of Congressmen William Keating and Stephen Lynch would change dramatically, putting the two into the same district unless Congressman Keating moves to his summer house on Cape Cod, something that he announced earlier this week that he would do. Cape Cod would be part of a new, incumbent free district that would stretch from the Cape and Islands across Plymouth and Bristol County to Fall River.
• Congressman Lynch would lose some Boston neighborhoods and would pick up the suburban city of Quincy and parts of the South Shore.
• Western Massachusetts communities currently represented by retiring Congressman John Olver would be split among the two districts currently represented by Congressman James McGovern and Congressman Richard Neal.
• Congressman McGovern’s Third Congressional District would expand westward to absorb Worcester, Hampshire, and Franklin counties as well as Northampton and Amherst.

“My thanks go out to our legislative leaders and members of the Joint Special Committee on Redistricting for coming together and completing this extraordinary task,” said Patrick. “The districts adhere to Constitutional guidelines and were created through an open and transparent process. Most importantly, these new districts are regionally balanced and reflect the Commonwealth’s diversity.”